This invention relates generally to power semiconductors, and more particularly to methods and systems for current sharing between parallel connected power semiconductors.
At least some known power converters utilize power semiconductor switches. The power semiconductor switches' current outputs may be coupled in parallel when a desired output current is greater than the current capability of one power semiconductor switch by itself. Imbalance in current sharing between semiconductor switches coupled in parallel limit an amount of total output current that may be produced by the power converter. More specifically, in such instances, the highest stressed power semiconductor switch limits the power converter output, such that the lower stressed power semiconductor switches do not achieve their full capability.
Generally, an output current of power semiconductor switches is at least partially dependent on the electrical characteristics of each power semiconductor switch. Another factor which may affect the output of power semiconductor switches is magnetic interaction between the magnetic fields generated by each output current, and/or magnetic fields generated by other current carrying conductors or other sources, for example, one or more current return paths. In limited applications, power semiconductor switches may be positioned to facilitate minimizing such effects. However, multiple magnetic field sources and/or unknown magnetic field sources may make balancing output currents between power semiconductor switches difficult to achieve.